I'm going to thumb up this game even though I completed only the first 3 levels of the game and I'm not going to bother continuing - at least not any time in the recent future. Reason being the game is GREAT for what it is - an ACTUAL old school platformer - with all its charms and its flaws.
The reason I personally am not going to bother playing more of the game is simply because I found the difficulty settings not doing it for me. The Normal difficulty is the right way to play the game - but like true old school platformers-style, it requires a couple of retries to complete a level. The checkpoints are quite farther apart, and there are limited lives. If you run out of lives, it's game over and you start the level all over from the beginning. The game does have the perfect amount of challenge on Normal, but I simply just don't have the patience or time for it.
The Easy difficulty on the other hand - gives you unlimited lives - I appreciated this change, but what bummed me out was that the bosses - which are the most satisfying part of the levels - die in few hits - making the game WAAY too easy. I feel there could've been an intermediate difficulty where you just get unlimited lives, but leave the boss difficulty the same as Normal. If at all that gets patched in, I would LOVE to get back into the game.
As it is right now, it's for a very niche audience - and I believe a simple intermediary difficulty setting between Easy and Normal would've definitely pleased me.